ST. PAUL — Environmental groups have dropped a lawsuit they filed against Minnesota regulators for allowing U.S. Steel’s Minntac mine to operate a waste pit with a long-expired permit.

That’s because the Minnesota Pollution Control Agency last month released a new draft permit that would impose stricter controls on wastewater discharges from the pit. Hudson Kingston of the Minnesota Center for Environmental Advocacy said that met the lawsuit’s primary goal.

The agreement for dismissal requires regulators to complete the new permit within nine months and for it to comply with the federal Clean Water Act. It also requires the MPCA to include the environmental groups in any mediation it enters with U.S. Steel over the permit. If those conditions aren’t met the groups can revive the lawsuit.